Abstract: this study is to further expand the application scope of computer simulation technology (CST) in complex environments, and promote the reform of ideological and political teaching in the era of big data. In this study, a set of computer simulation system for ideological and political teaching (I & P teaching) is constructed, and targeted research is launched from this. The main research results are as follows. Firstly, a computer simulation system for ideological and political teaching is designed based on Apriori algorithm and other theoretical foundations. The system has a three-layer structure: website (WEB) server, Mail server, and student terminal. The performance test and function test results reveal that when the maximum number of concurrent users is 500, the system can run normally with the maximum response time of 6.6s and the good-condition of various functions, so it can meet the actual needs of universities. Compared with the traditional I & P teaching mode, the proposed system can effectively improve the students’ attitudes towards ideological and political courses (I & P courses), increase their satisfaction and acceptance of I & P teaching, and contribute to the mastery of knowledge. Therefore, the designed system can realize good actual teaching effect and show reliable application value. In addition, the results of this study can provide scientific and effective reference materials for subsequent research on I & P teaching.